ECOLOGY

1. ECOLOGY ___________________________________ ORGANISMS POPULATIONS COMMUNITY SAME SPECIESLIVING TOGETHER IN AN AREA Ex: “herd” DIFFERENT POPULATIONS LIVING TOGETHER IN AN AREA BIOLOGY; Miller and Levine; Prentice Hall;2006

2. _______________________ _____________ ECOSYSTEMS BIOMES BIOSPHERE All the organisms that live in a place together with their NON-living environment Group of ecosystems that have same climate and similar communities The portion of the planet in which all life exists IMAGE SOURCES: see last slide

3. The scientific study of interactions of organisms with each other and with their environment = ______________ The portion of the planet in which all life exists = _________________ (includes land, water, atmosphere) ECOLOGY BIOSPHERE Extends from about 8 km above the Earth’s surface to 11 km below the ocean’s surface http://jaeger.earthsci.unimelb.edu.au/Images/Topographic/Whole_Earth/Earth_100.jpg

4. WHAT SHAPES AN ECOSYSTEM? BIOTIC FACTORS __________________ All the living things an organism interacts with __________________ All the non-living things that affect an organism Ex: climate, temperature, sunlight soil, humidity, wind ABIOTIC FACTORS Images from: Pearson Education Inc; Publishing as Pearson Prentice Hall

5. Habitat vs. Niche • Habitat= the area where an organism lives. • Niche= physical and biological conditions necessary for an organism to live; also, what it eats and who eats it.

6. The Earth is SOLAR POWERED! ALL LIVING THINGS USE ENERGY _____________ is the main source of energy for life on Earth. SUNLIGHT http://www.animation-station.com/smileys/index.php?page=17

7. AUTOTROPHS = PRODUCERSCan make their own food ALL LIVING THINGS USE ENERGY Most autotrophs use _______________ to capture solar energy Main producers on land = green plants In water = algae PHOTOSYNTHESIS BIOLOGY; MIller and Levine; Prentice Hall; 2006

8. HETEROTROPHS = CONSUMERS HERBIVORES ________________ = eat only plants ________________ = eat only animals ________________ = eat both plants & animals CARNIVORES OMNIVORES http://gallery.hd.org/_exhibits/natural-science/_more2003/_more09/elephant-eating-greenery-in-Addo-Park-Eastern-Cape-South-Africa-2-WL.jpg http://personal.ecu.edu/wuenschk/rabbit-wolf.gif http://www.rodsguide.com/bears/eating.jpg

9. HETEROTROPHS = CONSUMERS DETRITIVORES ________________ = feed on plant & animal remains EX: mites, earthworms, snails, crabs ________________ = break down and absorb organic matter EX: bacteria & fungi DECOMPOSERS http://montereybayphotos.com/images/nature/2.jpg http://www.fwnp.com/bracket-fungi.htm

10. TROPHIC LEVEL Each step in a food chain or web = _______________ ______________ ALWAYS make up the ________ trophic level. PRODUCERS FIRST http://home.insightbb.com/~g.mager/Pond/Ecosystem.htll

11. Lower levels must be bigger to support the level above. Only about_____ of the energy from each level is passed on. 10% http://home.insightbb.com/~g.mager/Pond/Ecosystem.htll

12. Some energy is used for life processes such as growth, development, movement, metabolism, transport, and reproduction. The rest is lost as ________ HEAT http://home.insightbb.com/~g.mager/Pond/Ecosystem.htll

13. Ways organisms interact COMPETITION ______________________ Between SAME and DIFFERENT kinds of organisms Compete with each other for available resources __________________________ Between DIFFERENT kinds of organisms Hunt and kill other organisms to supply their energy needs __________________________ Between SAME kind of organisms Live together and help each other __________________________ Between DIFFERENT kinds of organisms live in close association with another kind of organism PREDATION COOPERATION SYMBIOSIS

14. COMPETITION Organisms in an ecosystem have to compete with each other for available resources: FoodShelterMates

15. COMPETITION If resources are scarce, some organisms will starve and populations will decrease. If resources become more plentiful, populations will increase. Competition in nature often results in a winner and a loser . . . SURVIVAL OF THE FITTEST!

16. If a nutrient is in _____________OR __________________ it will LIMIT the growth of the population= _____________ SHORT SUPPLY CYCLES SLOWLY LIMITING FACTOR During this drought, there was not enough food available and many kangaroos starved. http://www.wspa-international.org/exhibition/gallery/large_DeadKenyan%20droughtSPANA.jpg

17. Food Chain: simple model of how energy and matter pass through an ecosystem

18. Food Web: series of interrelated food chains

19. Trophic Level: each “level” in a food chain

20. How organisms obtain their energy • Organisms that produce their own food are called autotrophs • Autotrophs include organisms that complete photosynthesis and chemosynthesis • Organisms that obtain nutrients from other organisms are called heterotrophs • Heterotrophs include those that eat only autotrophs and those that eat other heterotrophs

25. Producers • Autotrophs- organisms that capture energy from sunlight or chemicals and use that energy to produce food. • Photosynthesis- use light energy to create high energy sugars. • Chemosynthesis- use chemical energy to produce sugars. (bacteria do this)

26. Food Chains • A food chain is a series of steps in which organisms transfer energy by eating, and being eaten. • Energy always flows in one direction from autotrophs to heterotrophs. • Arrows show direction of energy flow!

27. Food Webs • When the feeding relationships in an ecosystem form a network of complex interactions. • Trophic level- each step in a food chain or food web. Producers make up the first trophic level, consumers make up the second, third, or fourth. 3C 2C 1C 1P

28.  • Biomass Pyramid- Represents the amount of potential food available for each trophic level in an ecosystem. • Biomass- The total amount of living tissue within a given trophic level. Measured as grams of organic matter per unit area. • Pyramid of Numbers- Based on the numbers of individual organisms at each trophic level. 

29. Ecological Pyramids • Energy Pyramid- Only about 10% of the energy available within one trophic level is transferred to organisms at the next trophic level. • Energy consumed is lost from life processes and as heat. 1% 10% 100%

30. Growth Curves • Exponential • growth occurs when the individuals in a population reproduce at a constant rate. • Logistic growth occurs when a populations growth slows or stops following a period of exponential growth.

31. Carrying Capacity • Represents the largest number of individuals that the environment can support. • Often labeled “K”

32. Limiting Factors • Limiting factor is a factor that causes a population growth to decrease. • Density Dependent limiting factors depend on population size. ex: competition, predation, parasitism • Density Independent limiting factors affect all populations, regardless of population size. ex: weather, natural disasters, clear cutting

33. Human Population Growth • Demography is the study of human population growth statistics • Demographers study growth rate, age structure, and geographic distribution • Unlike other organisms, humans are able to reduce environmental effects on growth by eliminating competition for food, increasing food production, and controlling disease organisms

34. Effects of birthrates and death rates • In the United States, declining death rates have a greater effect on total population growth than increasing birthrates • When fertility rates are high, there is higher human population growth unless the death rate is also high • The birthrate, death rate, and fertility rate provide clues to determining population growth rate

35. Other factors that affect population growth • Age Structure affects population growth because if most people are out of their child bearing years, the fertility rate is low • Immigration (moving in) and Emigration (moving out) do not affect the total worldwide population but, does affect national population growth rates